1933 ten, valve grind

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6350_William_French
Posts: 78
Joined: Wed Nov 20, 2019 10:27 am

Re: 1933 ten, valve grind

Post by 6350_William_French » Wed Nov 11, 2020 4:09 pm

Hi Gary
I was told to work to 1/8th inch to 3/16th inch for the contact area, so your figures sound OK. It is also important to try and get the contact area in the centre of the valve face.
from Bill French

phil_taylor
Posts: 164
Joined: Thu Nov 21, 2019 10:49 am
Location: Hampton Hill, Middlesex

Re: 1933 ten, valve grind

Post by phil_taylor » Wed Nov 11, 2020 4:50 pm

Hi Gary,
For the early engines I have worked on about a 1/16" min seat for inlet valves (about 60 thou) and about 3/32" for the exhaust seats. I open the ports to reflect this size (just over1.1" inlet bore, 1" exhaust) which improves the engine breathing and has not given me any problems - last engine did 50,000 miles with one valve grind. Bill's measurements are more traditional but not wrong. You take your choice!
Phil

GaryCullen
Posts: 28
Joined: Wed Nov 20, 2019 1:34 am

Re: 1933 ten, valve grind

Post by GaryCullen » Wed Nov 11, 2020 7:08 pm

Many thanks for that Phil and Bill.
Just the advice I was looking for.
Gary
Antipodes VAR

GaryCullen
Posts: 28
Joined: Wed Nov 20, 2019 1:34 am

Re: 1933 ten, valve grind

Post by GaryCullen » Sun Nov 15, 2020 11:18 pm

Hi All
I am considering whether or not to renew the valve guides whilst I am about to do a three angle cut/grind on the valve seats.
The valve guides would need to be replaced before seatcut/grinding.
I reported earlier that I thought the Guide wear wasn't enough to bother with renewing them.
However on inserting the valve seat cutting head into cylinder Exhaust #4 valve guides I noticed that there is a distinct wobble, more than I am happy with.
Trying the valve back in there reduced the wobble a bit but the thought remains.... whilst I have the engine apart..etc.
My question is can the old guides be drifted out cold and new ones drifted in with the engine still in the car?

cheers
Gary
Antipodes VAR

Rod
Posts: 33
Joined: Sun Nov 24, 2019 9:44 am

Re: 1933 ten, valve grind

Post by Rod » Mon Nov 16, 2020 9:14 am

I'm sure someone who has tried it will advise if it is *actually* practicable to drive out the guides with the engine in place, but my edition of T B D Service's 'Austin Cars' says it can be done "....the old ones can be driven out from the top and new ones driven in from the same direction. The distance from the top of the guide to the top of the cylinder block is 1-1/8 in. on pre war models...".
If you are going to drift new ones in, a well fitting drift is essential. Especially make sure there is no radius at the step in the drift where the 'valve guide sized' pilot is machined down from the main body of the drift. There is a real danger of splitting your new guide if there is a radius there [you can guess how I found this out in my younger days...]. Probably some sort of drawbolt arrangement to install the new ones is a more scientific approach. The other way around this is to have a chat to your friendly engine reconditioner and see whether they can come out to your site and fit K liners [thin-walled phosphor-bronze sleeves] to the existing guides; I seem to recall this is a reamer job and the K liners basically tap in without too much effort. We used to fit them regularly in earlier days to a certain Australian/US make when the integral valve guides in the head wore oval, it was substantially cheaper than the factory method of reaming to suit valves with oversize stems.

phil_taylor
Posts: 164
Joined: Thu Nov 21, 2019 10:49 am
Location: Hampton Hill, Middlesex

Re: 1933 ten, valve grind

Post by phil_taylor » Mon Nov 16, 2020 5:54 pm

Hi Gary,
Should be no problem but you probably have got to remove the adjusting screw first. The critical distance after insertion is from the bottom of the guide to the top of the tappet bush. (If you drive the guide too far you will not be able to insert the tappet at some later date without removing the camshaft.) You need copper or brass in contact with the top of the guide on the stepped drift or the guide will be damaged. It helps that the Club guides appear to be about 1/8" shorter than the Austin ones. I have only done the guides with engines in bits.
Cheers
Phil

GaryCullen
Posts: 28
Joined: Wed Nov 20, 2019 1:34 am

Re: 1933 ten, valve grind

Post by GaryCullen » Mon Nov 16, 2020 7:13 pm

Thanks Phil and Rod.
great advice as always.

Phil, I am assuming by " adjusting screw" you mean tappet adjusting screw?

I have a suitable drift turned down with a sharp shoulder but I will also turn down a brass collar for it to sit directly on the guide top.
My plan is to freeze the guides over night before inserting.

As an aside, I notice looking in the valve chest area there is one small hex headed bolt ( or set screw ) in each of the block castings that take a cam follower.
Is this some sort if adjuster or does it prevent the follower falling into the sump?

cheers
Gary
VAR NZ

Rod
Posts: 33
Joined: Sun Nov 24, 2019 9:44 am

Re: 1933 ten, valve grind

Post by Rod » Mon Nov 16, 2020 11:15 pm

Thanks for the endorsement Gary!
If the arrangements on your 10 are the same as the 6 cyl 14 (and I suspect they will be), I think the set screws you refer to in your third paragraph retain the tappet (aka cam follower) guide blocks on to the cylinder block itself.

bob_allison
Posts: 240
Joined: Wed Nov 27, 2019 3:20 pm

Re: 1933 ten, valve grind

Post by bob_allison » Wed Nov 18, 2020 1:09 am

Gary , I take it that you have tried the wear in the guides with a new valve ? The valves need to be an easy fit in the guide , they will heat up and expand when running , especially the exhaust , so you must have some slack . For the mileage which we do , I shouldn't worry unless the wear is gross .

Rod
Posts: 33
Joined: Sun Nov 24, 2019 9:44 am

Re: 1933 ten, valve grind

Post by Rod » Fri Nov 20, 2020 10:31 pm

Good point Bob, rule of thumb is 0.005" maximum rock with valve in its normally open position [bare valve-spring removed, of course]

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